In the story...
You are new, novice adventurers who the counsel doesn't take seriously
That's why when you report that the Soraks are real, they laugh at you and tell you to bring a head.
Then you find a magic crown, obviously an artifact level item, an extremely valuable one.
BUT somehow, they just let you keep it AND send you alone to find other gems in very dangerous places.
To me, the way the game story handles this isn't making any sense at all... If I was the council, I would never let the party keep the crown AND send you dangerous places with that artifact. Who cares if you die? After all you're still "nobody". And why send you elsewhere and risk losing it?
Suggestion 1 :
Make another reason, lore, dialogues, motivation, quest, anything that would explain how and why the party keeps the crown AND sent to dangerous quests.
Suggestion 2 :
Remove the crown from the PC,so head, the Crown will be kept in the city for further study. Do not change the main storyline, however add a special healing magic allowing to travel without the crown temporarily, but enough for a full voyage.
Suggestion 3 :
The crowned PC becomes unavailable, he stays in the city while the remaining party goes to the quest. In this case, another member, maybe a veteran from council, would join the party and replace him.